The receptor tyrosine kinase (RTK) family of cell surface receptors shows a high affinity to numerous growth signals. Although numerous intracellular signaling pathways are shared following activation of the receptors by ligand, the responses may be tightly regulated by ligand- receptor specificity or through variations in responses to specific receptors – the one receptor may induce differing results following stimulation depending on the cell type in which the receptor is expressed.

(source: Wikipedia)